3GPP Long Term Evolution, LTE, is the fourth-generation mobile communication technologies standard developed within the 3rd Generation Partnership Project, 3GPP, to improve the Universal Mobile Telecommunication System, UMTS, standard to cope with future requirements in terms of improved services such as higher data rates, improved efficiency, and lowered costs. The Universal Terrestrial Radio Access Network, UTRAN, is the radio access network of a UMTS and Evolved UTRAN, E-UTRAN, is the radio access network of an LTE system. In an UTRAN and an E-UTRAN, a User Equipment, UE, is wirelessly connected to a Radio Base Station, RBS, commonly referred to as a NodeB, NB, in UMTS, and as an evolved NodeB, eNB or eNodeB, in LTE. An RBS is a general term for a radio network node capable of transmitting radio signals to a UE and receiving signals transmitted by a UE.
For LTE to be turned into practice in an efficient manner it was decided that LTE support six different transmission bandwidths or system bandwidths, which are 1.4, 3, 5, 10, 15 and 20 MHz. This decision was made to be able to set requirements on the user equipments, UE:s, and network nodes in an efficient manner. At the time of decision it was found that these six transmission bandwidths would cover sufficiently most operator's spectrum allocations.
In addition, the LTE Rel-10 specifications of the 3GPP standard have recently been standardized, supporting aggregation of Component Carriers, CC. The Rel-10 standard support up to five aggregated carriers where each carrier is limited in the RF specifications to have a one of six bandwidths namely 6, 15, 25, 50, 75 or 100 resource blocks (corresponding to 1.4, 3, 5, 10, 15 and 20 MHz respectively). Carrier aggregation can in some cases also be used as a tool to allow different bandwidth sizes apart from the standardized transmission bandwidths. FIG. 2a shows a spectrum 200 comprising two aggregated transmission bands 200a and 200b (or carriers) of 5 Mz and 3 MHz. For example is it possible to allocate a channel bandwidth of 8 MHz by combining a 5 and 3 MHz carrier to a specific terminal, as disclosed in FIG. 2a. 
An operator may own a contiguous section of spectrum that does not match any of the existing channel bandwidths in LTE. However, e.g. depending on the operator's spectrum size it may not be feasible to rely on carrier aggregation as a solution to utilise the complete spectrum. The operator could then make the choice to deploy a different LTE carrier, which is different from the (at least up to release 11) supported LTE bandwidths, e.g. 7 MHz, for UE:s supporting such a solution and continue to operate e.g. a 5 MHz carrier for those UE:s that do not support 7 MHz. However, one must appreciate that there will always be a number of legacy terminals in the system. An option would then be to provide different transmission bandwidths for different UE:s.
However, it is a general problem to perform scheduling and demodulation on a carrier, where the transmission bandwidth is different for different UE:s. The different bandwidths create a problem since the Downlink Control Information, DCI, payload depends on the bandwidth of the carrier and if a user equipment assumes the wrong bandwidth it is unable to decode the DCI message
Furthermore, in some cases the transmission bandwidth does also impact the physical location or mapping, of the uplink control signaling which would be located at different location in frequency depending on which transmission bandwidth is used. This may also create problems for the UE not knowing which location to use.
Hence, the existing solutions are not well adapted for a system where different UE:s, e.g. legacy and new UE:s, see different transmission bandwidths.